The Murder She Wrote and Magnum P.I. crossover episodes

Jessica Fletcher lived in a small town where murder occurred so regularly that if it was a real place, Cabot Cove would literally be the murder capital of the world. 

In 1986, Murder She Wrote did a crossover episode with Magnum P.I. where the first part, "Novel Connection" played on Magnum P.I. The second part aired a few days later, on Sunday, on Murder She Wrote.